Date: Wed, 31 Jul 1996 16:13:27 -0700
From: dmk@Eng.Sun.Com (David Kahn)
Subject: Item #380: PCI: Include pci class code string in 'compatible'


P1275 Openboot Working Group Proposal -- Proposal #:380 Ver 1

Title:          PCI: Include pci class code string in 'compatible'

Author:         David Kahn

Date:           July 31, 1996

Ed/Tech:        Technical

Synopsis:       PCI: Include pci class code string in 'compatible'

Doc & Version:  PCI Binding, 1.75d as augmented by the June minutes

Problem:        In order to be able to chose an arbitrary and generic
		class code driver in the OS, the driver selection
		algorithm should be able to chose a class-code driver
		from the choices presented in the 'compatible' property.

		An example is chosing a class code driver for an
		arbitrary pci-pci bridge on systems where the host
		pci node is not a generic pci-pci bridge, but wants
		to use the name 'pci'.

Proposal:       

	Under probe-pci, in the creation of the 'compatible' property:

	[ Please refer to June minutes. I'm doing this based on the
	approved changes in the June minutes, which I believe leave
	this 'compatible' creation description a bit flawed ]

	"compatible" Construct a list of names in most-specific to
		least-specific order as defined in [4], with the
		most specific name first in the list derived from the 
		subsystem id, vendor id [ use existing text here ... ]
		The second entry in the list is in the form
		pciclassNNNNNN, where NNNNNN is the device class code.
		The last entry in the list is the generic form of the name [4],
		and may be omitted if there is no corresponding mapping
		to a generic form of the name from the device class code.

	[ The intent is to require this for bridges without FCode.
	  Do we need to say anything for devices with FCode? ]


[ P1275 Item #380 -- Received: Wed Jul 31 16:15:06 PDT 1996 ]